Modular High Temperat ure Pebble Bed React or • Modules added t o • 120 MWe meet demand. • Helium Cooled • No Reprocessing • 8 % Enriched Fuel • High Burnup • Built in 2 Years > 90,000 Mwd/ MT • Fact ory Built • Direct Disposal of • Sit e Assembled HLW • On--line Ref ueling • Process Heat Applicat ions - Hydrogen, wat er
For 1150 MW Combined Heat and Power St at ion VHTR Characteristics - Temperatures > 900 C Ten-Unit VHTR Plant Layout (Top View ) (distances in meters) - Indirect Cycle 0 20 40 60 80 100 120 140 160 0 - Core Options Available Admin - Waste Minimization 20 Equip Equip 9 7 5 3 1 Training Access Access Hatch Hatch Oil Refinery 40 Control 60 Equip Access 8 6 4 2 Bldg. 10 Hatch 80 Maintenance Parts / Tools 100 Turbomachinery Turbine Hall Boundary Primary island with reactor and IHX Hydrogen Production Desalinization Plant
Reference Plant Modular Pebble Bed Reactor Thermal Power 250 MW Core Height 10.0 m Core Diameter 3.5 m Fuel UO 2 Number of Fuel Pebbles 360,000 Microspheres/Fuel Pebble 11,000 Fuel Pebble Diameter 60 mm Microsphere Diameter ~ 1mm Coolant Helium
Indirect Cycle with Intermediate Helium to Helium Heat Exchanger Current Design Schematic 800 ° C 520 ° C 69.7 ° C 280 ° C 126.7kg/s 8.0MPa 7.75MPa HPT MPC2 HPC 52.8MW 26.1 MW 26.1MW Reactor core 799.2 C 6.44 MPa Intercooler 900 ° C 7.73MPa 69.7 C 4.67MPa IHX LPT LPC MPC1 52.8MW 26.1 MW 26.1MW 509.2 ° C 522.5 ° C 7.59MPa 350 ° C 7.89MPa 30 C 7.90MPa 719. ° C 125.4kg/s 2.71MPa Bypass 5.21MPa Valve Circulator Inventory control PT 136.9MW Precooler Generator 326 ° C 96.1 ° C 105.7kg/s 511.0 ° C 2.73MPa 2.75MPa 115 ° C Recuperator 1.3kg/s 69.7 ° C Cooling RPV 1.3kg/s
Features of Current Design Thermal Power 250 MW Gross Electrical Power 132.5 MW Net Electrical Power 120.3 MW Plant Net Efficiency 48.1% (Not take into account cooling IHX and HPT. if considering, it is believed > 45%) Helium Mass flowrate 126.7 kg/s Core Outlet/Inlet T 900°C/520°C Cycle pressure ratio 2.96 Power conversion unit Three-shaft Arrangement
Top Down View of Pebble Bed Reactor Plant Reactor TOP VIEW Vessel WHOLE PLANT Plant Footprint Recuperator Module IHX Module Precooler HP Turbine LP Compressor ~77 ft. MP Compressor MP Turbine Turbogenerator LP Turbine Intercooler #1 Intercooler #2 HP Compressor ~70 ft. Power Turbine
PLANT MODULE SHIPPING BREAKDOWN Total Modules Needed For Plant Assembly (21): Nine 8x30 Modules, Five 8x40 Modules, Seven 8x20 Modules 8x30 Power Turbine Module Six 8x30 IHX Modules Six 8x20 Recuperator Modules 8x20 Intercooler #2 Module 8x40 Piping and Precooler Module 8x40 Piping & Intercooler #1 Module 8x30 Upper Manifold Module 8x30 Lower Manifold Module 8x40 HP Turbine, LP Compressor Module 8x40 MP Turbine, MP Compressor Module 8x40 LP Turbine, HP Compressor Module
Example Plant Layout Secondary (BOP) Side Hall Primary Side Hall Reactor Vessel Turbomachinery Recuperator Modules IHX Modules NOTE: Space-frames and ancillary components not shown for clarity
Space Frame Technology for Shipment and Assembly Everything is installed in the volume occupied by the space frame - controls, wiring, instrumentation, pumps, etc . Each space frame will be “plugged” into the adjacent space frame .
“Lego” Style Assembly in the Field
Space-Frame Concept • Standardized Frame Size • Stacking Load Limit Acceptable • 2.4 x 2.6 x 3(n) Meter – Dual Module = ~380T • Standard Dry Cargo Container • Turbo-generator Module <300t • Attempt to Limit Module Mass to ~30t • Design Frame for Cantilever Loads / 6m – Enables Modules to be Bridged – ISO Limit for 6m Container • Space Frames are the structural supports – Stacking Load Limit ~190t for the components. – ISO Container Mass ~2200kg • Only need to build open vault areas for space frame installation - RC & BOP – Modified Design for Higher vault Capacity—~60t / 12m module • Alignment Pins on Module Corners • Overweight Modules – High Accuracy Alignment – Generator (150-200t) – Enables Flanges to be Simply – Turbo-Compressor (45t) Bolted Together – Avoid Separating Shafts! • Standardized Umbilical Locations – Heavy Lift Handling Required – Bus-Layout of Generic Utilities – Dual Module (12m / 60t) (data/control)
Reactor Vessel Present Layout IHX Vessel High Pressure Turbine Low Pressure Turbine Compressor (4) Power Turbine Recuperator Vessel
Main IHX Header Flow Paths
Plant With Space Frames
Upper IHX Manifold in Spaceframe 2.5 m 10 m 3 m
Distributed Production Concept “MPBR Inc.” S i t e a Component Design n d A s s e Space-Frame Specification m b l y S p e c i f i c a t i o n s Management and Operation Component Component Assembly Fabricator #1 Fabricator #N Contractor e.g. Turbine e.g. Turbine Manufacturer Manufacturer Site Preparation Contractor MPBR Construction Site Labor Component Transportation Design Information
Economics Is Bigger Always Better ? Andrew C. Kadak Professor of the Practice Massachusetts Institute of Technology Center For Advanced Nuclear Energy System s Center For Advanced Nuclear Energy System s CANES
Key Issues • Capital Cost • Operations and Maintenance • Fuel • Reliability • Financial Risk Perception • Profitability - Rate of Return • Competitiveness Measure - cents/kwhr CANES
Key Cost Drivers • Safety Systems Required • Time to Construct • Staff to Operate • Refueling Outages • Maintainability • NRC Oversight Requirements CANES
Safety Systems • The more inherently safe the design the fewer safety systems required - lower cost • The fewer safety systems required the less the regulator needs to regulate - lower cost • The simpler the plant - the lower the cost • The more safety margin in the plant - the lower the cost CANES
Time to Construct • Large Plants take longer than small plants • Modular plants take less time than site construction plants • Small modular plants take less time than traditional large unit plants to get generation on line. CANES
Modular Plants ? • Are small enough to be built in a factory and shipped to the site for assembly. • Modular plants are not big plants divided into four still big pieces. • Small Modular plants can be designed to be inherently or naturally safe without the need for active or passively acting safety systems. CANES
Factory Manufacture • Modularity allows for assembling key components or systems in the factory with “plug and play” type assembly at the site. • Navy submarines are an example. • Minimize site fabrication work • Focus on installation versus construction. • Smaller units allow for larger production volume CANES
Economics of Scale vs. Economies of Production • Traditional view - needs to be bigger to improve economics • New view - economies of production may be cheaper since learning curves can be applied to many more units faster. • Answer not yet clear • Function of Design and ability to modularize CANES
Operations • More complex the plant, the higher the operating staff. • The more corrosive the coolant, the more maintenance and operating staff. • The more automatic the operations, the lower the operating staff. • Plant design is important CANES
Refueling Outages • Cost Money • Create Problems • Reduce Income • Require higher fuel investment to keep plant operating for operating interval • On-line refueling systems avoid these problems CANES
Reliability • More components - lower reliability • More compact the plant, the harder to replace parts. • Access to equipment is critical for high reliability plants • Redundancy or quick change out of spare components quicker than repair of components CANES
Financial Risk Chose One Option A Option B • Cost $ 2.5 Billion • Cost $ 200 million • Time to Build 5 Years • Time to Build 2.5 years • Size 1100 Mwe • Size 110 Mwe • Regulatory Approval to • Regulatory Risk - 2 years Start up depends on events • Build units to meet in 5 years. demand • Interest During • Income during Construction High construction of 1100 Mwe CANES
Internal Rate of Return • New Paradigm for Deregulated Companies • Rate Protection no longer exists • Need to judge nuclear investments as a business investment • Time value of money important • Merchant Plant Model most appropriate • Large plants are difficult to justify in such a model CANES
Competitiveness • Capital Cost/Kw important but that isn’t how electricity is sold. • Cents/kwhr at the bus bar is the right measure • Includes capital, operations and maintenance and fuel • Addresses issues of reliability, maintainability, staff size, efficiency, etc. CANES
Conclusions • Bigger May Not be Better for economics or safety. • Economies of Production are powerful economies as Henry Ford knew. • Market may like smaller modules • Market will decide which is the correct course - Big or Small. CANES
Anything Nuclear Competitive With Coal or Natural Gas? • ESKOM (South Africa) Thinks So • Pebble Bed Reactor Busbar Cost Estimate 3.5 cents/kwhr. • Capital Cost < $ 1500/kw • Operating Staff for 1100 Mwe plant -85 • Plans to go Commercial – 2011/12 • MIT/INEEL Working on Pebble Bed Reactor Design CANES
Plant Target Specifications • Rated Power per Module (Commercial) 165 MW(e) • Net Efficiency >43% • Four/Eight-pack Plant 660/1320 MW(e) • Continuous Power Range 20-100% • Module Construction Schedule 24 months (1st) • Planned Outages 30 days per 6 years • Seismic 0.4g • Aircraft (Calculations to survive) 747/777 • Overnight Construction Cost (2004 $, 4pack) <$1500/kWe • Fuel Costs & O&M Costs 9 mills/kWh • Emergency Planning Zone <400 m • Availability >95%
Commercialization Approach (PBMR) • Strict adherence to life cycle standardization • Series build program to capture learning experience Total plant design responsibility because of closely coupled Brayton • cycle Modularization and shop fabrication key elements to quality, short • delivery time and competitive costs Strategic international suppliers as integral part of delivery team • Mitsubishi Heavy Industries (Japan) Turbo Machinery Nukem (Germany) Fuel Technology SGL (Germany) Graphite Heatric (UK) Recuperator IST Nuclear (South Africa) Nuclear Auxiliary Systems Westinghouse (USA) Instrumentation ENSA (Spain) Pressure Boundary Sargent & Lundy (USA) Architect/Engineer Services
“All-in” Generation Costs <3.5 Cents Initially • Capital Overnight Costs • Operating and Maintenance Costs • Fuel Costs • Owner’s Other Costs – Insurance – Licensing Fees – Spent Fuel Waste Disposal Fees – Decommissioning Funding
Comparison of PBMR Capital Cost Economics (Nth 4-pack) Base and Advanced Designs 400 MWth 400 MWth 500 MWth @ 900°C @ 1200°C @ 1200°C Total Net Output - MWe 688 880 1100 Net Thermal Efficiency - % 43 55 55 U.S. Price - $/kWe <1500 <1200 <1000 1.5 • Smaller configurations lose some • “economies of repetition” Relative Overnight Capital Cost • advantages of full SSC sharing 1 • Modularization in factory offset this effect to some degree for SSCs that are common to all configurations • 8 pack configurations provide even 0.5 greater economies of scale due to 1 2 3 4 5 6 7 8 additional sharing of non-safety No. of Modules in Multi-pack structures and systems
System and Commodities Comparison • System Comparison LWR PBMR Total Plant Systems/Structures 142 68 Safety Systems/Structures 47 9 • Commodities Comparison LWR PBMR Rebar (tons/MWe) 38 16 Concrete (cubic yards/MWe) 324 100 Structural Steel (tons/MWe) 13 2
Potential for Cost Savings from Full Shop Fabrication is High • High percentage of plant cost in relatively few components with high learning curves Low civil works cost • • High erection and project services cost Scope of Supply Item Percentage of Total (%) LWR PBMR Nuclear Island Equipment 34 40 Civil Works 25 9 Conventional Island Equipment 15 13 Erection 11 20 Project Services, including Commissioning 9 13 BOP Equipment 6 4 Capture Full Benefit by Module Fabrication, Assembly, and Testing
Learning Curves for Plant Cost Elements • Different curves used for each element of cost structure • Rate depends on how often repeated during plant construction • Limited by “flattening point” • PBMR unique components will have higher learning than more standard components • Field activities have low learning • Learning depends on degree of complexity, automation, and mechanization in fabrication process Component Percentage Reduction (%) Flattening Point (Plant No.) Turbo Machinery 54 7 Reactor Internals 35 3 Reactor Pressure Vessel 26 3 Fuel Handling and 33 9 Storage System (FHSS) Reactivity Control and 26 3 Shutdown System (RCSS)
Commercial PBMR Composite Learning Comparison (Without Full Potential Realized) PBMR RSA 1.0 • Approximately 30% curve cost reduction 0.9 PBMR USA • Generally curve 0.8 conservative DOE* report compared to what has curve 0.7 been achieved Korean plants 0.6 EDF PWR • Shows difference in series regional 0.5 implementation 1 4 7 10 13 16 19 22 25 28 31 8-Pack Plants as a result of labor productivity and wage rates
Some Specifics on Full Factory Production • Skid-mounted equipment and piping modules developed as part of detailed design Electric and I&C installed on • modules with cabling All inspections and commissioning • testing possible completed in factory • Interfaces with other systems, structures, and components (SSCs) engineered into design
Shared Systems – Additional Opportunities for Multi-Module Plants • Helium Inventory Storage: 1 x 200% capacity • Helium Purification: 2 systems • Helium Make-up: 2 stations • Spent Fuel Storage: 10 years capacity • Used Fuel Storage: 2 x 100% capacity tanks • Graphite Storage: 2 x 100% capacity tanks • HVAC blowers and chillers • One Remote Shutdown Room • One set of Special Tools • One Primary Loop Initial Clean-up System • Selected Equipment Handling • Fire Protection Reservoirs and Pumps • Generator Lube Oil System & Transformer (shared per 2 modules)
Ten-Unit MPBR Plant Layout (Top View) (distances in meters) 0 20 40 60 80 100 120 140 160 0 Admin 20 Equip Equip 9 7 5 3 1 Training Access Access Hatch Hatch 40 Control 60 Equip Access 8 6 4 2 Bldg. 10 Hatch 80 Maintenance Parts / Tools 100 Turbomachinery Turbine Hall Boundary Primary island with reactor and IHX CANES
Compet it ive Wit h Gas ? • Nat ural Gas 3.4 Cent s/ kwhr • AP 600 3.6 Cent s/ kwhr • ALWR 3.8 Cent s/ kwhr • MPBR 3.3 Cent s/ kwhr Relat ive Cost Comparison (assumes no increase in nat ural gas prices) based on 1992 st udy
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